Method and a system for filling goods in bags from a coherent series of bag members

ABSTRACT

In connection with the packaging of items or loose material in sheet packings it is known to use a web of cohering flat bag members, which is successively conveyed to a filling station, in which the bag members are opened, one by one, for filling and subsequent closing and separation from the web. The free mouth edges of the bag members or the web are profiled for supported conveyance on opposed carrier rods, tubes or gripping chains which, just before the filling station, diverge from each other for effecting opening of the bag members. The invention provides for a flat bag web, the upright edge strip portions of which are caused to be folded down over respective opposed carrier chains. These strip portions are prepared with a row of perforations which, by the down-folding, are moved down into holding contact with holding pins upwardly projecting from the carrier chains, whereby a very safe carrying and conveying engagement is obtained without any special profilation of the mouth edges and with a simple design of the carrier chains.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention concerns a method and a system for the packing ofitems in bags of foil, which in a coherent web are fed through a fillingstation in which a filling of the individual bags is effected, and whichare then closed and separated from the coherent web in the formation ofindividual packages.

2. Description of Related Art

A basic example of this technology is described in EP-696997, where itis disclosed that the opposing upper edge areas of the bag web areprovided with bent-over channel—forming edge parts for drawing in oncarrier rods, which in the feeding direction have a mutual enlargementto bring about an opening of the bags, so that these can be filled, e.g.through an overlying filling funnel, after which the carrier rods areagain drawn in towards one another for provisional closing of the filledbags. The bags can then finally be closed by being welding together downunder the said channel part, after which they are cut over and mutuallyseparated. It is disclosed as an alternative that instead of the channelparts, use can be made of thickened edges which can be introduced intoslotted carrier tubes for a quite corresponding feeding forwards of thebags.

There have since been suggested other forms of means used for thegripping and supporting of the opposing upper edges of the bag web, e.g.as disclosed in EP 0 555 31 B, where use is made of special grippingchains for this purpose, without any special requirements concerning theconfiguration of the upper edge areas of the folded bags. This is ofparticular importance, in that as starting point a simple, rolled-up webof flat foil without local thickenings can be used, but on the otherhand there are considerable problems both with regard to the control ofthe opposing bag edges for secure engagement with the gripping chainsand with regard to a desirable inexpensive configuration of thesechains.

Moreover, in EP 0 825 116 it is disclosed that operations can be carriedout with a closed, flat tubular web of foil, which can be continuouslycut up along its upper edge, with associated integrated folding out andgripping of the upper edges thus cut up, without these being speciallyconfigured either as channels or with thickenings, which constitutes adistinct simplification of the requirements concerning the formation ofthe bag web. The cut-up upper edge parts are folded out for clampingbetween respectively moved belts which are provided with longitudinaldepressions and corresponding pressing-in strings, whereby a suitablyfirm support engagement can be established.

However, this engagement is no more firm than axial slipping can occurbetween the upper edges of the bag web and the associated belt conveyormeans, whereby uncertainty can arise concerning the degree to which anitem being fed has been fed forward with the conveyor belts in a fullysynchronous manner. Moreover, deviations can arise with regard to theheight at which that area of the web sides which are clamped between theconveyor belts lies, which can be of significance with regard to whetherthe filled bags are finally closed at precisely the place at which theclosure is intended, e.g. seen in relation to printing on the bag.

SUMMARY OF THE INVENTION

With the present invention, it has been found possible to use therelevant cutting-up and folding-out of the upper edge areas in order toachieve a reliable and quite firm gripping of the edge areas, i.e. whenthese are provided beforehand with a simple row of small holes, and whenin the folding-out and the hereto related pressing-down, care is takenthat the pressing-down at least of the one side, but preferably at bothsides, is effected in such a manner that these holes are placed downover upright holding pins on a feeding chain. In a simple manner, therecan hereby be established a completely firm and well-defined supportengagement without the bag being required to have any thickening at theupper edge, and without the carrier chains having to be configured in acomplicated manner with special, controllable gripping means, in thatthey merely require to be provided with said upright holding pins. Theformation of the edge holes can be effected in a quite simple manner,especially because the holes along the two upper edges areas can beformed in the same operation.

Correspondingly, the carrier chains can thus be moved freely through asequence in which, in the filling station, they will draw the folded-outweb edges out from each other in such a way that the bags are herebyopened for the filling with products from above or possibly from theside. Hereafter, the web edges can again be brought together with theview to the final closing and cutting-free of the filled bags. It willbe without importance for the feeding accuracy whether a certain pull onthe bag web arises during the feeding, in that this will safely be fedsynchronously with the support chains.

The invention also comprises a bag filling machine and a packaging lineconfigured for the execution of the method according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be explained in more detail withreference to the drawing, in which

FIG. 1 is a schematic perspective view for the illustration of theinvention,

FIG. 2 is a plan view of a bag web according to the invention, and

FIG. 3 is a side view of a holding pin used in the system according toFIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 it is shown that a web of foil material 4 can be unwound froma supply roll 2, said web consisting of a double foil folded up around abottom edge 6, and which along the upper edge is closed by a simplewelding 8 without any bending-over or thickening of any kind. Therefore,this can also be said to be a tubular foil. In the web there are anumber of slots 10 which extend from the bottom edge 6 up to a distancebelow the top edge 8, so that the web appears with mutually separatedbags 12, the side edges of which are closed by welds 14. Just above thetop of the slots 10, the double web is cut through at respectivehorizontal lines 16 which extend a short distance out to both sides ofthe related slots 10.

Between the top edge 8 and the cut lines 16, the edge portion of the webis broken through by a single row of perforated holes 18.

This forwardly-influence web 4, which instead of being rolled up canbest appear in a supply box in zig-zag folded form, is unwound at afilling aggregate on a support rod or support rail 20 which extends froma fixed support part 22 of the aggregate and serves for the simplesupport of the closed top edge 8 of the web 4.

Slightly in front of the support part 22, the support rod 20 has anupwardly-extending knife element 24 which, when the web 4 is pulledforwards, will continuously cut up the upper edge of the web, andhereafter there is arranged a continuing support system consisting ofopposing, parallel chain drives 26 which are provided with uprightholding pins 28 for engagement with the holes 18 in the respective upperedge parts 4 laid out to both sides, and by a pressure roller 30 whichafter the threading-in of the foil web serves to press the saidfolded-out upper edge areas of the web 4 down against the fixedunder-supported carrier chains 26 into horizontal contact against theupper sides of these, and hereby during the swinging-down of the holes18 in such a manner that the holes 18 are swung down and engage over thechain pins 18. The pressure roller 30 is configured with annular grooves32 to provide free passage for the outer end parts of the chain pins 28,and in these grooves there are bedded transverse pins (not shown) whichin a gearwheel-like fashion can co-operate with the chain pins 28 forautomatic, synchronous driving of the pressure roller 30.

Hereafter, the opposing upper edge parts of the web 4 will be firmlyanchored to the support pins 28, and the carrier chains can thus becontrolled forward through a desired sequence for successive opening ofthe bags as indicated at 34, and for the closing of the bags after theyhave been filled. It is not considered necessary to describe this inmore detail. However, it should be noted that the pins 28 are disposedin the chains' neutral lines, so that the bag web is not exposed tostretching or slackening during passages with changes in direction.

With a closing of the bags by welding immediately below the top of theslots 10, and possibly a subsequent cutting-off, the filled bags areseparated from the remaining part of the web which is rolled up asexcess material.

It must be mentioned that on the fixed support part 22 it is preferredto place a guiding element with a double-bladed ploughshare shape whichactively brings about or initiates the shown folding-out of theperforated edge areas of the web, whereby improved security can beachieved with regard to the essential function, which the controllingdown of the holes over the pins 28 constitutes.

In FIG. 2 it is shown that instead of said holes 18, it can be preferredto use star-shaped perforations 18′, in that in the formation of thesethere will not be any problems with regard to stamped-out small parts.

As indicated in FIG. 2, a spot-welding assembly 5 can be effectedbetween the opposing web sides in the part areas in between the bags.The object of these assemblies, which can be pulled apart, is todemarcate an upper longitudinal channel for engagement over the supportrod 20 and the stabilising of the web on this rod.

In FIG. 3 it is shown that the pins 28 can be pointed towards the top inorder to ensure a more safe engagement in the star perforations 18′, andalso configured with a lower recess 36 which will serve to provide extraretention of the web edge area when this has first been broughtcompletely down over the pin.

What is claimed is:
 1. A method for the packaging of items or loosematerials in foil bags comprising the steps of: feeding verticallyoriented, unfilled foil bags as a coherent web through a filling stationin which a mouth of each bag is held open for filling with the items ormaterials; filling the foil bags with the items or materials; closingthe filled foil bags; separating the filled foil bags from the web,wherein a mouth edge of the unfilled foil bag web is brought intocontrolled connection with a feeding means comprising two horizontal,opposed carrier chains having freely upstanding pins arranged to secureand feed opposing bag mouth edges between the carrier chains along apath through a filling station by forcing the mouth edges of theunfilled foil bag away from each other and folding the mouth edges outfrom each other for successive folding down onto and securing to saidfeeding means for successive opening of the bags at the filling stationand, after filling of the unfilled foil bags, bring the mouth edges ofthe filled foil bags together for the closing of the filled foil bags,and wherein the mouth edge of each vertically oriented, unfilled foilbag has a strip edge area provided with a series of holes or starperforations which are folded down and brought into holding engagementwith the upstanding pins on the carrier chains by successively pressingthe holes or star perforations down over said upstanding pins.
 2. Anapparatus for the packaging of items or loose materials in foil bagscomprising a filling station for filling the foil bags with the items ormaterials, a separation means for separating the filled foil bags from aweb of foil bags, the apparatus further comprising: feeding means forfeeding vertically oriented, unfilled foil bags as a coherent webthrough the filling station in which a mouth of each unfilled foil bagis held open for filling with the items or materials wherein a mouthedge of the unfilled foil bag web is brought into controlled connectionwith the feeding means, said feeding means comprising two horizontalopposed carrier chains having freely upstanding holding pins, saidholding means being arranged to secure and feed opposing bag mouth edgesbetween the carrier chains along a path through the filling station afolding means for forcing the mouth edges of the unfilled foil bag awayfrom each other and folding the mouth edges out from each other, apressure means positioned after said folding means for successivepressing down and securing the mouth edges to the carrier chains toenable successive opening of the bags at the filling station, and aclosing means bringing the mouth edges of the filled foil bags togetherfor the closing of the filled foil bags, and wherein the mouth edge ofeach vertically oriented, unfilled foil bag has a strip edge areaprovided with a series of holes or star perforations, wherein saidfolding means folds down said strip edge area and said pressure meansbrings said series of holes or star perforations into holding engagementwith the upstanding holding pins on the opposed carrier chains bysuccessively pressing the holes or star perforations down over saidupstanding pins, and wherein the upstanding holding pins on the opposedcarrier chains engage the respective opposed mouth edges of the bag webtowards and through the filling station.
 3. The apparatus according toclaim 2, wherein the pressure means comprises a pressure roller which isconfigured with annular grooves which allow free passage of theupstanding holding pins.